Locomotive



ll. i a o a a WILLIAM E. 'WGQDARD, 0F FOREST HILLS,

LGCOMO'TEVE.

Application files hecember 26, 1922. Eerie We. ceases...

To all whom 2'25 'ma-g/ concem Be it known that I, VVILLIAM E. Woomno, a citizen of the United States, residing at l ores'c Hills, in the county of Queens and State of New York, have invented certain new and useful Improvements in Locomo tives, of which bhe following is a lion. p a I p This invention renam locomotives and its nature, objects and advantages will be best understoodfroin the following brief description of certain of the difficulties eucoun'tered in present practice.

In locomotive design, the factor of adhesion of the drivers for the respective classes of locomotives to meet the requirements of the service ifor which the locomotive is intended, is so well defined and established and varies within such narrow limits that there may be said to be a standard or normal factor of adhesion for the various locomotives. If the factor of adhesion were low, there wouldbe ez'zcessive wheel slippage making it even impossible, in some cases, to start a train, lec alone keeping it in-motion at slow spee ds without stalling; while if it were high, among other things, the operation would not be economical in consumption of steam, which latter can be obtained best with a low factorof adhesion.

Hence, the normal factor adhesion of existing practice represents compromise, and, therefore, really meets neither condition satisfactorily; for in starting and at slow speeds there is still objectionable slippage at the peaks of the "torque curve and econonly in steam consumption is not what it should be.

ll; is one of the primary objects of my invention to rovjde a locomoizive which meets these con ifiions satisfactorily and which shall have the possibilities of the steam econonly incident to a low factor of adhesion (lower than the normal factor) and yet have the ability to start a train and sustain motion at'slow speeds withoutstalling incident to a hi h factor of adhesion (higher than the normal factor).

I accomplish the foregoing, together with such other objects as may hereinafter appear, or are incident to my invention by means of a construciion, the preferred form of which I have illustrated in the acconn panying drawings, or which:

lg. 1 is a diagrammatic side elevation of specificaa locomotive embodying my invention; and Fig. 2 is a torque curve illustralsing the operation and certain of the advantages tliereof. Y

Referring now to Fig. l, the locomotive, i general, is of a construction now in use but the factor of adhesion of the main drivers '1' is well below the normal factor of adhesion of a locomotive of this class, the locomotive shown being of the 2-8-2 or Mikado type having a normal factor of adhesion of approximately a. The elements determining the factor of adhesion are the weight upon drivers, the diameter of she drivers, the diameter and stroke of the pistons, and the operating pressure. For a given type of locomotive or class of service, the weight", on drivers, the diameter of she drivers, and the stroke of the pistons are well established, and while it might be possible to alter the factor of adhesion by varying one of bhcse elements, this does not present the same po sibilities in economy that a variation in the operating pressure or diameter of the pistons does. I, lherefore, propose :30 decrease the factor of lhesion of the main drivers either by an increase in operatin pressure or an increase in piston diameter, preferably the latter. The cylinders 8 are thus of larger diameter than standard and the locomotive may be said to be ovencylindered.

By using large cylinders, is follows that at line higher speeds the engine may be worked, at shorter" out oils than customary for a given draw bar horse ower; and the shorcer fihe cut off, the greater the economy in steam consumption for the reasonlhai; the steam is used more expansively in the cylinders than is possible with a locomotive having cylinders of scandard size. Thus, in hauling he same load, a locomotive built in accordance with my invention will operate are shorter cu' 'c oil's and with the resultant improved steam economy compared wish a loco-- motive of standard conch-notion, or, stated otherwise, a greater load may be hauled wi'bh substantially the same sceam consump" tion. I Wish such low factor of adhesion, however, there would be excessive'wheel slip page and consequent loss of power and. possibility of stalling. This slippage occurs at the peaks of the torque curve which is an irregular cunve with marked hi -h poinw even in locomotives sizanclavo i but this frequently results I tor 9 iscarriedon drives the Wheels -10 -'.curve A and that Such a curve is illustrated in Fig. 2 at A.

pressure relying on the mon'ientum of the train to move the engine to point Where a i'resh grip may he had on the rail or to a ower portion of the torque curve, in stalling be cause of the reduction in draw bar pull. Tho'reason this isdone is because the coeflicient sol friction, is much when the Wheels slip With respect to the rail. 1 pro-- poseto carry the locomotive over the torque peaks should the main drivers start to slip by means of an auxiliary motor and driving mechanism which moves the locomotive until a fresh grip may he had by the main drivers. This'auxiliary driving mechanism has a factor of adhesion preferably considerably higher than the normal factor and, in theembodimcnt shown, the auxiliary mothe trailer truck end thereof, such Wheels generally being of small diameter. 7 i

he torque curve of this driving mechanism is illustrated at B in Fig. and it will be observed that it is much flatter than the the peaks are also much closer together and bear no relation to the peaks of the curve A, i. e., they are not in synchronism.

The operation of the auxiliary motor in starting and at slow speeds, therefore, reduces slippage of the main drivers because it sustains motion and thus tends to maintain a grip of the niain drivers on the rail:

flhe sustained motion" immediately checks lncipient vvslipp age.

y the construction described, I have made it possible to successfully operate a locomotive with a. factor of adhesion normally prohibitive and therebysecured the benefits in, steam economy resultant from the useoi largercylinders, While at the same time for time the locomotive can start the train and sustain motion.

Steam is supplied to the auxiliary motor by the pipe 12 connected to the main steam supply line zit-13, the pipe 12 being con trolled by a throttle l4.

What l. claim is:

l. The combination of locomotive having an appreciably greater proportion of tractive power to Weight on drivers than normal for the particular class of locomotives, and an auxiliary motor and driving mechanism for carrying the locomotive over the torque peaks at which slippage of the engine drivers would occur.

2. The hcreinbei'ore described process of operating a locomotive having an appreciahly greater proportion of traotive power to Weight on drivers than normal for the particular class or locomotives Which consists in aiding the main drivers over the torque peaks in starting and slow speeds and thereafter operating the locomotive at relatively short cut oil's as compared to standard pram the particular type and class of service.

3. The herein described process of operating a locomotive having appreciably overpowered cylinders for the particular class of locomotives which consists in aiding l the main drivers over the torque peaks in starting and at'slow speeds by an auxiliary motor mechanism andiwheels, the factor of adhesion of which is relatively high.

4. The combination With a locomotive appreciably over-cylindered for the particular class, of an auxiliary motor and driving mechanism carrying the locomotive over the torque peaks at which slippage of the engine drivers would occur.

In testimony whereof, I have hereunto signed my name,

WILLIAM E. WOQDARD. 

